There is so much info in the Organic Method Primer UPDATE on diseases. In
the index under viral diseases, it lists potato, pg 411, which lists lef
roll, mop-top, virus X, Virus Y.
There is a note about callose protection.
If you are concerned about how aphids work, in relation to disease, there
is something on why high nitrogen content of leaf attracts insects, loline
natural insecticicde, and more on aphid as an insect--general--2 pages,
and a page listing different types of pahids and what to do about getting
rid of them--predators, etc.
So?? The basic premise of organic growing is that the healthy plant does
not normally get insect attack, because it send out the right kind of
electromagnetic frequenies. The insect, whether aphid or other, recognizes
it does not want to eat that plant.
Maybe there is something in these 3 pages of use to you. The book should
be in the university library, as it is the most comprehensive in the world
on the subject, and so easy to find info by the detailed index.